The Titanic actress is confirmed to be replacing Karen Gillan (Amy Pond) as the assistant to Matt Smith's Time Lord in the BBC sci-fi show's seventh series. Coleman's debut episode will air at Christmas.
> Doctor Who: Jenna-Louise Coleman - The press conference in full
Speaking at BBC's Broadcasting house this morning, she said that she was a "huge fan of the show", commenting: "I'm beyond excited, I can't wait to get cracking; working alongside Matt I know is going to be enormous fun and a huge adventure.
"Matt Smith did my audition with me. It was fun and I felt like we were in it together."
Coleman also revealed that her personal favourite companions were Billie Piper and Karen Gillan.
Showrunner Steven Moffat said: "It always seems impossible when you start casting these parts, but when we saw Matt and Jenna together, we knew we had our girl. She's funny and clever and exactly mad enough to step on board the TARDIS.
"It's not often the Doctor meets someone who can talk even faster than he does, but it's about to happen. Jenna is going to lead him his merriest dance yet. And that's all you're getting for now. Who she's playing, how the Doctor meets her, and even where he finds her, are all part of one of the biggest mysteries for the Time Lord ever."
> Jenna-Louise Coleman: Ten Things about the new Doctor Who star
Moffat confirmed that Doctor Who will air six episodes in 2012 and a further eight in 2013 for the show's 50th anniversary. In total, series seven comprises of 14 big, blockbuster-movie episodes.
The writer also dropped hints about Gillan and Arthur Darvill's departures, claiming that it would involve a final encounter with the Weeping Angels and that not everybody would make it out alive. "And I mean it this time," added Moffat.
Rumours that Coleman, who has also appeared in Emmerdale and Waterloo Road, had been cast in the show first emerged this morning,
Gillan was confirmed to be departing Doctor Who along with co-star and on-screen husband Arthur Darvill (Rory Williams) back in December.
It is known that they will leave part way through series seven in a "heartbreaking end", and Gillan has teased that her exit will have a "strong impact".
She also described her final Doctor Who storyline as a "damn good" one that will see Amy go out "on a high".
Watch Karen Gillan discuss her Doctor Who departure with Digital Spy below:
Scroll through our gallery of past Doctor Who companions below: